export { }

type UserType = {
  name: string
  age?: number
}

const users:UserType[] = [
  { name: '波老师', age: 18 },
  { name: '苍老师' },
  { name: '潘老师', age: 16 }
]

users.forEach(item=>{
  console.log(item.age)
  console.log(item.age)
})